Certain small power driven units require a clutch and/or a brake for safety purposes. The driven member may consist of a blade of a lawnmower. A number of clutches have been devised but have many shortcomings.
The invention herein is directed to a quick acting clutch with a driving clutch drum of friction material which is directly connected to an engine and a driven pair of clutch shoes which are pivotally connected to flyweights. The advance in this design relates to the greater leverage for the centrifugal forces acting on the flyweights resulting in higher forces with smaller flyweights. Thus, the pivoted shoes permit greater leverage which distribute the forces over a larger area of the clutch shoes and drums and does so by wearing evenly. Accordingly, unit stresses on the friction material of the cylindrical drum are lower with consequent lower wear.
Prior to this invention, flyweight clutches had highly stressed nose portions which rapidly wore the cylindrical drum and occasionally caused crumbling failures.